This limited-edition Pentax fixed lens that came out in 2009 is a pancake lens with a focal equivalent of 24mm on a full-frame camera… so it isn’t a very wide-angle lens. Compact, it measures 39.5mm long and weighs in at 212g. It will certainly adapt very well to the upcoming Pentax K01 that we hope to be able to test quickly.

The optical formula of this 15mm lens integrates a low-dispersion (ED) glass element to limit chromatic aberrations, and an aspherical element (AL) to correct distortion.

Note that this limited edition has benefited from particular attention to quality and finish. Although it’s difficult to verify the ways in which its manufacture is different, the number of lenses produced per day has been deliberately limited to better control per-unit quality.

Pentax offers two choices at nearly the same price, this 15mm f/4 lens and a 14mm f/2.8 lens. Photographers who prefer compactness will want to seriously consider the 15mm f/4, even though the 14mm f/2.8 is slightly brighter.

In terms of image quality, the two lenses are fairly close. Although the 15mm f/4 better controls both distortion and chromatic aberrations, its overall results are hampered by its weak resolution and its serious lack of uniformity in the field.

Conclusion

The SMC DA 15mm F4 ED AL Limited is an interesting lens that we wish were brighter. While its control of distortion is remarkable, its resolution is a bit weak, which is a shame, since it means that photographers will not be able to take full advantage of the Pentax K5’s 16Mpix sensor. In short, this lens could be improved to better appeal to those looking for a compact wide-angle.